Technologies for deodorization, sterilization, and toxic gas decomposition, based on a plasma developed by a high-voltage pulse discharge, have recently been put to use. To generate such a plasma, a high-voltage pulse generating circuit capable of supplying extremely narrow high voltage pulses is required.
There has heretofore been proposed a high-voltage pulse generating circuit, such as disclosed in Patent Document 1, for example. As shown in FIG. 10, the high-voltage pulse generating circuit 200 is formed with a simple circuit arrangement, including a transformer 204, a first semiconductor switch 206, and a second semiconductor switch 208, which are connected in series across a DC power supply unit 202. The first semiconductor switch 206 has an anode terminal connected to one end of a primary winding of the transformer, and wherein the other end thereof is connected to the cathode of a diode 210. The diode 210 further has an anode connected to the gate terminal of the first semiconductor switch 206.
When the second semiconductor switch 208 is turned on, the first semiconductor switch 206 is rendered conductive, thereby applying a voltage from the DC power supply unit 202 to the primary winding of the transformer 204, and storing induced energy in the transformer 204. When the second semiconductor switch 208 is thereafter turned on, since the first semiconductor switch 206 is quickly turned off, a sharply rising extremely narrow high-voltage pulse Po is developed across the secondary winding of the transformer 204. Therefore, the high-voltage pulse Po appears between the output terminals 212, 214 of the transformer 204.
The high-voltage pulse generating circuit 200 has a simple circuit arrangement, which is capable of supplying a high-voltage pulse Po having a sharp rise time and an extremely short pulse duration, without requiring a plurality of semiconductor switches to which high voltages are applied.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2004-72994